JP4491181B2 - Disposable articulated spacing device for surgical treatment of human joints - Google Patents

Abstract

A disposable articulated spacing device for the treatment of joints of the human body, particularly for temporary replacing an explanted joint prosthesis, comprises at least one first member (2) able to be secured to a first articulation end and at least one second member (3) able to be secured to the other articulation end, both said members (2, 3) being pre-formed and made entirely of biological compatible and porous material suitable to be added with pharmaceutical and therapeutical products; the pre-formed members (2, 3) are reciprocally coupled in an articulated manner to maintain a suitable joint space and at least a partial articulation for the time necessary to perform the further implantation of a joint prosthesis. The biologically compatible and porous material is chosen among metals, metallic alloys, organo-metals, ceramics, glasses, plastics materials, bone cements and combinations thereof. The articulated spacing device maintains a suitable space in the joint seat while allowing a considerable articulated mobility, and re-establishes suitable conditions of implantation of a new permanent joint prosthesis.

Description

[0001]
TECHNICAL FIELD The present invention is generally applicable to surgical procedures for articulation of the human body, and in particular, joints that need to be explanted due to septic or aseptic failure due to failure of artificial joint implantation. Related to disposable spacing devices for temporary replacement of the prosthesis .
[0002]
According to the known surgical “double stage” method, the spacing device can be held in the joint seat as long as necessary to reconstruct the most favorable condition of implanting a new prosthesis. .
[0003]
Background Art It is a well-known fact that artificial joints such as knees, hip joints, heels and elbows must be removed frequently for various reasons and mainly due to local infection after surgical implantation.
[0004]
In such cases, the defective prosthesis cannot be replaced directly with a new prosthesis, and the joint seat must be treated with an appropriate antibiotic prior to surgery.
[0005]
On the other hand, in order to prevent joint space shrinkage, tissue retraction, joint atrophy and loss of muscle elasticity and tension, the space within the joint must be preserved.
[0006]
Spacing devices are known for use in two-stage implantation of artificial joints to treat both the hip and knee.
[0007]
Italian patent application VR95A000072 describes a disposable spacing device for a hip prosthesis , the essential features of which are made from a biocompatible substrate of the type used for bone cement. There is to be.
[0008]
Are known also some distance retainer for a knee joint made by the surgeon's hand at the time of surgery, these instruments are made from a block of the standard type of bone cement comprising active ingredient at will.
[0009]
A disadvantage of these known processing methods is that they cannot preserve the space in the joint in an ergonomically and anatomically correct state. Moreover, preparation takes time and the surgeon's hard work increases, reducing the success rate of the operation.
[0010]
To overcome these shortcomings, spacing devices have been made that use appropriate anatomical and ergonomic molds that are filled in-place with bone cement. However, these known spacing devices do not allow the joint to move, and as a result, a long-term rehabilitation is required after the permanent prosthesis is reimplanted.
[0011]
In yet another case, the spacing device is obtained by lining a bone cement to a metal permanent prosthesis. This method provides temporary articulation, but is difficult to make, and despite the use of cement-backed prostheses , There is a need to place in infected seats that the surgeon considers as an infectious agent that makes symptoms worse.
[0012]
DISCLOSURE OF THE INVENTION The main object of the present invention is to provide an articulating spacing device that is disposable and easy to use for surgeons. This device can be implanted directly into, for example, the knee, hip, heel or elbow joint seats when replacing an existing prosthesis that must be removed due to septic or aseptic failure.
[0013]
Another object is to provide a disposable articulating spacing device that can maintain the proper joint space in the healing environment for the time required to successfully reimplant a new permanent prosthesis.
[0014]
Another object is to provide a disposable articulation spacing device that allows correct articulation and temporary implantation anatomical and ergonomic shapes.
[0015]
Yet another object is to provide a disposable articulation spacing device that can be easily implanted into and out of the joint location.
[0016]
Yet another object is to provide a disposable articulating spacing device that has reduced joint friction to improve joint mobility and improve the quality of life of hospitalized patients.
[0017]
These and other objects, which will become apparent from the description herein below, are disposable articulation spacing retention for temporarily replacing an explanted permanent joint prosthesis for treatment of a human joint. Achieved by the instrument . That is, according to claim 1, the device comprises at least one first member that can be attached to the first joint end and at least one second member that can be attached to the second joint end. Preformed and made entirely from a biologically compatible porous material suitable for adding pharmaceuticals, both the preformed members are necessary for implanting a new permanent joint prosthesis Can be articulated to each other so as to maintain an appropriate joint space for a period of time and maintain at least partial mobility in an articulated state, initially with the preformed member (2,3) Is free of pharmaceuticals, and the preformed member (2, 3) has porosity in its substrate or has an appropriate cavity formed in its outer surface and absorbs or absorbs by direct contact By insertion into the cavity It characterized in that it can be added filled with liquid solution form medicament to said preformed member immediately before implantation of the device (2, 3).
[0018]
Preferably, the above-mentioned biologically compatible porous material is selected from among metals, metal alloys, organometallics, ceramics, glass, plastic materials, bone cement and combinations thereof.
[0019]
Suitably, the pharmaceutical agent can be selected from among medically active ingredients, antibiotics and radioactive opacifiers and can be added to a preformed member.
[0020]
When the articulation spacing device replaces the knee joint, the pre-formed member consists of a femoral member that consists of a generally shell-like object and reproduces the femoral condylar process and a resected tibial flat A tibial member consisting of a columnar body that can replace the part is included.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION Further features and advantages of the present invention will become more apparent in light of the following detailed description of a disposable articulating spacing device provided as an example only, with reference to the accompanying drawings. You will understand clearly.
[0022]
Referring to the accompanying drawings, there is shown a disposable articulation spacing device for temporarily replacing a joint prosthesis explanted from a human body.
[0023]
The articulation spacing device generally indicated by reference numeral 1 comprises at least one first member 2 that can be attached to the first joint end and at least one second member 3 that can be attached to the second joint end. Composed.
[0024]
According to the present invention, both members 2, 3 are pre-formed and made entirely of a biocompatible porous material, and in a healing environment for the time required for reimplantation of a new permanent joint replacement. They are connected to each other in an articulated state so as to maintain an appropriate joint space and to provide at least partial mobility to the joint.
[0025]
Preferably, the biologically compatible porous material can be selected from among metals, metal alloys, organometallics, ceramics, glass, plastic materials, and combinations thereof.
[0026]
Specifically, the plastic material can be selected from thermoplastic polymers such as acrylic resin, polyethylene, and polypropylene that can be thermoformed by blow molding or injection molding.
[0027]
As an alternative method, the plastic material can be selected from among resins that can be cured by radical polymerization, such as acrylic resin and polyester, and can be formed by cooling.
[0028]
As is known per se, radical polymerization can be accelerated by suitable chemical catalysts such as benzoyl peroxide and initiators or physical accelerators such as ionizing radiation, gamma rays, ultraviolet light.
[0029]
In a particularly preferred embodiment, the biologically compatible porous material forming the members 2, 3 is used in bone cement, for example in Italian Patent Application No. VR95A000072 filed by the applicant. It is what.
[0030]
The preformed members 2, 3 can be pre-added with a suitable pharmaceutical agent selected from active medical ingredients, antibiotics and radioactive opacifiers.
[0031]
On the other hand, the pharmaceutical can be added to the preformed member just prior to implantation of the device by absorption by direct contact or filling an appropriate cavity formed on the outer surface of the preformed member.
[0032]
The drug in liquid solution is easily absorbed into the device by the pores of the device 's basic material and then released after implantation into the joint seat.
[0033]
Conveniently, the preformed members 2, 3 are made of various sizes to accurately fit different patients. Moreover, these members will provide a means to secure them to the joint ends.
[0034]
The embodiment of the spacing device 1 shown in the figures is designed to be inserted into the knee joint.
[0035]
The preformed member 2 is a tibial member and the preformed member 3 is a femoral member.
[0036]
In particular, the thigh member 3 comprises a first adjacent face body 4 designed to occupy the space left by the explanted metal prosthesis. Preferably, this adjoining face body 4 is substantially “U” shaped, i.e., a horseshoe shape, in plan view, having side portions 4 ′, 4 ″ and a central recess 5. The external contact surface 6 of the adjacent face body 4 has a curved portion that can reproduce the curvature of the femoral condyle.
[0037]
The tibial member 2 comprises a second adjacent face body 7, which is substantially columnar and slightly curved and has a suitable thickness. The adjacent face body 7 in plan view has a curved internal contact surface 8 and internal recess 9 to resemble a resected tibial flat and is generally “U” shaped, ie, a horseshoe.
[0038]
The contact surfaces 6 and 8 of the members 2 and 3 are formed so as to be able to perform a rotary translational movement when the limb is bent and extended.
[0039]
Moreover, the contact surfaces 6 and 8 have a good surface finish so that the joint can move considerably and have a low coefficient of friction.
[0040]
Both members 2, 3 may be provided with protrusions or rod-like end portions 10, 11, respectively, for attachment to the respective joint ends with bone cement, for example.
[0041]
In use, the surgeon first removes the existing infected joint prosthesis and cleans the joint space. The surgeon then selects an appropriate spacing device comprising pre-formed members 2, 3 that are adapted to the size of the patient.
[0042]
If the pre-formed members are pre-filled with active ingredients or pharmaceuticals during their formation, the surgeon will ensure that these members are securely fastened to the joint ends and that these members are articulated to each other. Implant these members while ensuring that the joint is at least partially movable.
[0043]
Conversely, if these members are not yet filled as described above, the surgeon may immerse these members in a solution of the active ingredient, or in-situ or pre-formed outer surfaces of the members. Several cavities are filled with the active ingredient, and finally these members are implanted in the joint seat, and these members are fixed to the joint ends by suitable fixing means or bone cement.
[Brief description of the drawings]
[0044]
FIG. 1 is a front view of a first component of a spacing device of the present invention.
FIG. 2 is a side view of the component shown in FIG.
FIG. 3 is a plan view of the components shown in FIG.
FIG. 4 is a front view of another component of the spacing device of the present invention.
FIG. 5 is a side view of the component shown in FIG. 4;
6 is a plan view of the components shown in FIG. 4. FIG.
7 is a perspective view from above of the component parts of the instrument illustrated in FIGS. 1-3. FIG.
FIG. 8 is a perspective view from the bottom of the component part of the instrument illustrated in FIGS.
FIG. 9 is a side view of the components shown in FIGS.
FIG. 10 is a top perspective view of the components shown in FIGS.
11 is a perspective view at an arrangement position of two components shown up to FIG. 10. FIG.
FIG. 12 is a side view of another embodiment of the spacing device of the present invention.

Claims (13)

A disposable articulation spacing device for temporarily replacing an explanted permanent joint prosthesis for treatment of a human knee joint, wherein the first articulated spacing device can be attached to a first joint end. It comprises one member (2) and one second member (3) that can be attached to the second joint end, and both members (2, 3) are pre-formed and suitable for adding pharmaceuticals as a whole. Made from a biologically compatible porous material, the preformed members (2, 3) provide the appropriate joint space for the time required to implant a new permanent joint prosthesis. The pre-formed members (2, 3) can be articulated to each other so as to maintain and maintain at least partial mobility in an articulated state, wherein the pre-formed members (2, 3) include an external contact surface (6 lordosis extending toward the other end from the femoral member (3) and one end having a) In to the one end and the spacing holding device having a thickness and a different tibial member (2) at the other end has an internal contact surface (8), initially in the preformed member (2, 3) pharmaceuticals Not included, the preformed member (2,3) has porosity in its substrate or has an appropriate cavity formed in its outer surface, absorbing by direct contact or the appropriate A gap-holding device characterized in that liquid medicine can be added and filled into the preformed members (2, 3) immediately before implantation of the device by insertion into the cavity.   The biologically compatible porous material is selected from metal, metal alloy, organometallic, ceramic, glass, plastic material, bone cement, and combinations thereof. Spacing device.   The spacing device according to claim 2, wherein the plastic material is selected from thermoplastic polymers such as acrylic resin, polyethylene, and polypropylene that can be thermoformed by blow molding or injection molding.   The spacing device according to claim 2, wherein the plastic material is selected from a resin that can be cooled and molded.   The spacing device of claim 1, wherein the biologically compatible porous material is bone cement.   The spacing device of claim 1, wherein the medicament is selected from among active pharmaceutical ingredients, antibiotics and radioactive opacifiers.   The pre-formed members (2, 3) have a condylar process that reproduces the curvature of the femoral condyle, and are formed so as to allow rotational translational movement of the condylar process when the limb is bent and extended. The spacing device according to claim 1, wherein the spacing device is provided. The pre-formed members (2, 3) have the external contact surface (6) and the internal contact surface (8) , the friction coefficient of which is set so as to improve the mobility of the joint. Item 8. The spacing device according to Item 7.   9. The pre-formed member (2, 3) according to any one of claims 1 to 8, characterized in that it is made in various sizes to fit any patient. Spacing device.   The spacing device according to claim 1, characterized in that the pre-formed members (2, 3) comprise fixing means for attachment to the joint ends.   11. A spacing device according to claim 10, characterized in that the fixing means each comprise a projection or a rod-like end portion (10, 11).   The spacing device according to claim 1, characterized in that the preformed members (2, 3) can be fixed to the joint ends with bone cement.   The femoral member (3) is composed of a first object (4) having a substantially shell shape to reproduce the femoral condylar process, and the tibial member (2) is a predetermined replacement for the excised tibial flat part. 2. A spacing device according to claim 1, characterized in that it consists of a substantially columnar second object (7) having a thickness of.

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